Presence of δ-(l-α-Aminoadipyl)-l-Cysteinyl-d-Valine in Fermentations ofPenicillium chrysogenum

Abstract

Cultures ofPenicillium chrysogenum, growth with [35S]sulfate or labeled amino acids, were examined by ion-exchange chromatography for possible peptidic precursors of penicillin. A sulfur-containing compound, present in both the mycelial extracts and the culture filtrates, was eluted at the location of the syntheticlld-tripeptide δ-(l-α-aminoadipyl)-l-cysteinyl-d-valine. Since this compound was also labeled when the cultures were incubated withdl-[6-14C]α-aminoadipic acid,l-[3,3′-3H]cystine, ordl-[1-14C]valine, its identity with the syntheticlld-tripeptide can be accepted. No δ-(l-α-aminoadipyl)-l-cysteine orlll-tripeptide were detected. The implications of these findings for tripeptide and penicillin biosynthesis are discussed.